Bitmap fonts are not covered by copyright: <https://cdn.loc.gov/copyright/history/mls/ML-393.pdf>, <https://cdn.loc.gov/copyright/history/mls/ML-443.pdf>
It is vector fonts, which can contain copyrightable code, which can be copyrighted.
It is vector fonts, which can contain copyrightable code, which can be copyrighted.
With vector fonts containing copyrightable code, are you referring to e.g. TrueType hinting, or OpenType shaping (or very avant-gardely, WASM shaping)? I should hope the glyph-drawing instructions don't fall under this definition of code, because that'd maybe mean SVG `path`s are copyrightable...
What specifics you can get is all described in ML-443.